Fig. 5

Cardiac Ca²⁺ handling and contractility in sibling, Tg-plnb^wt and Tg-plnb^R9C 9 dpf zebrafish larvae expressing mCyRFP1-GCaMP6f. A) Ratiometric images from beating hearts and their corresponding ventricular Ca²⁺ traces from representative sibling, Tg-plnb^wt and Tg-plnb^R9C larvae. B) HR, ventricular CaT amplitude, ventricular Ca²⁺ rise and decay rates, contraction and relaxation velocities, ESV, EDV, SV, FS, FAC and CO in sibling (n = 26), Tg-plnb^wt (n = 17) and Tg-plnb^R9C zebrafish larvae (n = 31). Statistical analysis was performed using a one-way ANOVA test with Tukey's multiple comparisons post-test. C) Diagrams of the ventricular diameter (μm) vs. ventricular Ca²⁺ levels (ratio) from the 3 and 9 dpf representative sibling, Tg-plnb^wt and Tg-plnb^R9C larvae shown in A. D) Pearson's correlation test between the decay time of CaT and EDV from 9 dpf sibling (n = 26) and Tg-plnb^R9C (n = 31) zebrafish larvae. E) Relative expression levels (qPCR) of plnb and atp2a2a in 9 dpf Tg-plnb^wt, Tg-plnb^R9C and sibling larvae (n = 3, 3 and 4 pools of ten hearts each, respectively). GADPH was used as a normalization control. Data are shown as mean ± SD, (* p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001).